Safety device for punch presses



Dec. 10, 1929. E. DES ENFANTS, sR 1,738,872

SAFETY DEVICE FOR PUNCH PRESSES Filed March 2'7, 1928 Educitd besfnianfsg VMW meme. 5

Patented Dec. l0, i929 UNITED STATES PATENT OFFICE EDWARD DES ENFANTS, 83., OF LUDINGTON, MICHIGAN, ASSIG-NOR TO HANDY THINGS MANUFACTURING COMPANY, OF LUDINGTON, MICHIGAN, A CORPORATION OF raromenn SAFETY DEVICE FOR PUNCH PRESSES Application filed March 27, 1928. Serial No. 265,128.

This invention relates to a safety device for punch presses, and is more particularly concerned with a novel structure of this type which is automatically operated by the ram of the punch press so that whenever the ram makes a downward movement, a brushing member is moved across the table on which the die is located acting to move the hand of the operator, which may be in the way, out of danger. A further object of the invention is to provide a construction which may be readily applied to punch presses and which has a large number of adjustments, making it applicable to many sizes of presses. A still further object of the invention is to construct the brushing member of the device in such a manner that when moved in one direction, if it should come against the hand of the operator of the punch press, it will be released so as to pass over the hand of the operator before injury thereto has taken place and yet at the same time will serve as an effective warning for the operator to remove his hand from danger. These and many other objects and purposes of the invention will be apparent as an understanding of the invention is had from the following description taken in connection with the accompanying drawing, in which,

Fig. l is a front elevation of a punch press having my invention applied thereto.

Fig. 2 is a fragmentary horizontal section and plan illustrating the manner of adjustably mounting the device on the press.

Fig. 3 is a horizontal section through the lower part of the brushing member, and

Fig. i is a fragmentary elevation of the lower part of the brushing member showing the same released and shifted to a different position so as to avoidinjury to the hand of the operator.

Like reference characters refer to like parts in the different figures of the drawings.

The punch press includes the usual table 1 on which the die 2 is fixed, above and at the rear side of which is a vertical supporting member 3 having guides 4 at its front side for slidably mounting the ram 5 of the punch press, at the lower end of which the punch 5 to cooperate with the die 2 is secured. It is to be understood that the ram is mounted for vertical reciprocatory movements and is driven by the usual overhead shaft in the usual manner, which, as it is not new and forms no part of the present invention, is not specifically illustrated or described.

At the upper end of the vertical support 8 and at the front side, a horizontal bar 6 is permanently secured. This bar is equipped with a horizontal slot 7 and the front face of the bar above and below said slot is provided with a consecutive series of teeth 8, as shown.

The safety device to be applied to the punch press is connected with the bar 6. A bell crank 9 has a bolt 10 passing through the elbow thereof and through the slots 7 in the bar 6. A washer 11 with teeth 12 at it rear side to pass in a recess between any two consecutive teeth 8 lies against the bar 6 and around the bolt 10. The bolt is threaded at its rear end and receives a clamping nut 13 whereby the structure is securely mounted but may be adjusted to any one of a large number of positions in the length of the bar 6.

A rod 14 extends substantially horizontally from one arm to the bell crank 9 and has a plurality of spaced apart grooves 15 cut therearound it, as shown. A block 16 is secured to the arm 14 and extends downwardly therefrom, a stirrup 17 extending over the arm and being attached to the block 16 by a pin which passes therethrough and seats in any selected groove 15, it being evident that the block 16 may be adjusted to several clifferent positions on the rod 14;.

A rod 18 threaded at its lower end is pivotally connected at its upper end to said block 16, the threaded lower end of said rod being screwed into one end of a turnbuckle 19. A second rod 20 threads at its upper end into the lower end of the turn-buckle and at its lower end is pivotally connected to a block 21 which in turn is permanently secured to a bracket 22 fixed to one side of the punch press ram 5. It is evident that on movement of the ram during the operation of the machine, the bell crank 9 is oscillated about the axis of the bolt 10. The turn-buckle 19 together with the adjustable connection of the member 16 to the rod 142 permit a wide range of adjustment so as to control the extent of position of the rod 24 so that it may be readily raised or lowered. Adjacent the lower end of the rod 24 a U-shaped elongated clip 26 of sheet metal is located, the legs of the clip normally embracing and frictionally engaging the lower end portion of the rod 24.

This clip is pivotally connected atits upper end 27 to the rod 24. A plate 28 is attached, by welding or riveting or in any other 7 suitable manner, to the U-shaped clip 26 and extends below the same, being curved at its lower end portion to the right as shown in Figs. 1 and 4, and at its outer face carries a F treme position shown in dotted lines.

fabric pad 29.

In the operation of the punch press the 0scillation of the bell crank 9 causes the plate 28 with its fabric face 29 to sweep back and forth across the upper side of the table 1 in front of the die 2. NVhen the ram is in its upper position, as shown in Fig. 1, this memher is to the left of the dieand the Work may be placed between the punch and die, but on thedownward movement of the ram the rod 24 with the attached fixture at its lower end swings to the right and eventually to the ex- If the operator has neglected to remove his hand f from a position of danger the fabric 29 on the plate 28 comes thereagainst and moves the hand to the right out ofdanger. It will be evident that this movement in front of the ,punchand die is practicallycompleted before the ram has made'more than one half of its downward movement; and the construction is such that the limits of the swing of the brushing member in either direction may be I very easily adjusted so as to insure removal of the hands of the operator of the machine before the danger position of the ram on its downward movement is reached.

' It many' times occurs that after the brushing member has been moved to the right to the position shown in dotted lines in Fig. l

the operator gets his hands in the way there of when' it is making its return movement,

thisresulting in injury, which while not of nearly as serious a nature as that caused by I "the'punch press, is liable to be very painful due, to the metal plate 28 at its lower end scraping over the knuckles of the hand.

To insure against this the U shaped clip is pivotallymounted at its upper end, as described,

so that if'the hand is in the way on the return movement'of the brushing movement said member may swing about the axis of the pivot 27, as shown in Fig; 4, whereupon the plate 28 of the brushing member will ride over the hand of the operator without injury thereto. The clip 26 frictionally grips the rod 24 with suflicient strength to normally hold the brushing member in the position shown in Fig. l, but the clip is yieldable to permit movement from the position to that shown in Fig. 4 when necessary.

The construction described is very practical and serviceable and has so proved in practice. Thewide range of adjustment permits the device to be adjusted to substantially any condition under which a press operates and also permits the attachment of the device to many different sizes of presses.

The appended claims define the invention which is to be considered comprehensive of all forms of structure coming within the scope of said claims.

I claim:

1. In a punch press having a vertically reciprocating ram and a support therefor, a horizontal slotted bar attached to the upper end of the support at the front side thereof,

a bolt extending through the slot in said bar ,1.

and adjustably mounted to be positioned at different positions in the length of the slot, a bell crank mounted to oscillate about said bolt, said bell crank having downwardly and outwardly extending arms, a rod adjustably mounted on the downwardly extending arm of the bell crank for adjustment lengthwise to different positions, a sweep pivotally connected to the lower end of the rod, yielding means normally holding the sweep in fixed position with respect to the rod but yieldable to release the sweep to swing in one direction away from said rod, and means connecting the outwardly extending arm of the bell crank with said vertically reciprocating ramwhereby the bell crank is oscillated on vertical movement of said ram.

2. In a punch press having a vertically reciprocating ram and a support therefor, a bell crank mounted for oscillation about a horizontal axis at the upper end and at the front of said support, said bell crank having downwardly extending and outwardly extending arms, a downwardly extending rod adjustably connected to the downwardly extending arm to the bell crank and adapted to be adjusted vertically with respect thereto, a U-shaped clip pivotally connected to said rod a short distance above its lower end,

said clip being adapted to yieldably embrace sald rod in one position, a sweep secured to said clip and means connecting the outwardly extending arm of the bell crank with said ram for oscillating the bell crank on reciprocation of the rain.

3. In a punch press having a vertically reciprocating ram and a support therefor, a bell crank pivotally mounted to oscillate about a horizontal axis at the upper end and at the front of said support, said bell crank having downwardly extending and outwardly extending arms, a rod connected with the downwardly extending arm of the bell crank and extending in a downward direction, an elongated channel shaped yielding clip pivotally mounted at its upper end on said rod a short distance above the lower end thereof, a sweep attached to said clip extending below the lower end of the rod, and means connecting the outwardly extending arm of the bell crank with the ram to oscillate said bell crank on reciprocation of the ram.

4. In a punch press having a vertically reciprocating ram and a support therefor, a rod pivotally mounted on said support adjacent the upper end thereof to swing back and forth in front of said ram, a sweep pivotally connected at its upper end to said rod a distance above the lower end thereof, means carried by said sweep to normally yieldingly engage with said rod but releasable there from to swing away from the rod in one direction, and means interposed between said ram and said rod for swinging the rod and attached sweep back and forth on reciprocation of said ram.

In testimony whereof I aflix my signature.

EDWARD DES ENFA NTS, SR. 

